I switched off the AC power today when I retired yet another casualty of my War on Rats -- the voltage stabiliser -- and the laptop battery kicked in; the display also dimmed perceptibly. Nothing wrong, except that when I moved back to AC power, the dimness persisted.
Per KPowersave my current hardware settings don't allow me change the display brightness. I booted into Windows and tried to install the Acer software that came along with the laptop, but it seems my machine is not an Acer laptop, most probably because Windows is only installed via VMWare.
I am currently left with no option to tweak the brightness. Shouldn't there be some OS-independent, hardware-level mechanism to do this? Some tiny knob somewhere, or a special function key?
Update: Duh. There is a function key combination right under my nose -- Fn + Right Arrow -- for this. To think I wasted nearly half a day mucking around with things like pbbuttonsd and pbbcmd.